This invention relates in general to subsea wellhead equipment, and in particular to an apparatus used to remotely lock wellhead components together. The present invention insures repeated locking of a subsea wellhead system, or a subsea connector or other subsea tubular members without sustaining permanent deformation in the apparatus itself.
Tubing hangers and tree caps have members that can be secured with locking mechanisms known as split rings. While successful, split rings are known to permanently deform after a single expansion. The present invention relates to a radially expandable and contractible slot lock ring for subsea wellheads, tubing hangers, subsea Christmas trees, a tree caps, subsea connectors or any number of tubular members used in the subsea oil and gas industry. The slot ring is capable of sustaining incredible force due to pressure end loads after expansion yet is pliable enough to return to its original shape when retracted.
The present invention replaces the conventional split locking rings, such as taught in U.S. Pat. No. 4,211,149 and incorporated by reference herein. Typical split locking rings are not capable of great elasticity after an initial deformation. They are incapable of coming back to their original shape after being expanded to lock into its mating component.
The present invention utilizes a unique pattern of cuts, grouped in slots, at specific distances from each other, which enable the solid ring to be deformed and then contract without loosing shape. The slot lock ring is actuated by straight axial motion by a tubular actuator having an actuating profile that engages an angular profile on the slot lock ring opposite the locking teeth of the slot lock ring.
The present invention provides a unique solution, which improves the maintenance needs for subsea wellhead or subsea equipment.